1 files changed, 80 insertions, 0 deletions
diff --git a/arch/x86/mm/kmemcheck/smp.c b/arch/x86/mm/kmemcheck/smp.c
new file mode 100644
index 000000000000..cd17ddfda082
--- /dev/null
+++ b/arch/x86/mm/kmemcheck/smp.c
@@ -0,0 +1,80 @@
+#include <linux/kdebug.h>
+#include <linux/notifier.h>
+#include <linux/smp.h>
+
+#include <mach_ipi.h>
+
+#include "smp.h"
+#include <asm/irq_vectors.h>
+
+static spinlock_t nmi_spinlock;
+
+static atomic_t nmi_wait;
+static atomic_t nmi_resume;
+static atomic_t paused;
+
+static int nmi_notifier(struct notifier_block *self,
+	unsigned long val, void *data)
+{
+	if (val != DIE_NMI_IPI || !atomic_read(&nmi_wait))
+		return NOTIFY_DONE;
+
+	atomic_inc(&paused);
+
+	/* Pause until the fault has been handled */
+	while (!atomic_read(&nmi_resume))
+		cpu_relax();
+
+	atomic_dec(&paused);
+
+	return NOTIFY_STOP;
+}
+
+static struct notifier_block nmi_nb = {
+	.notifier_call = &nmi_notifier,
+};
+
+void kmemcheck_smp_init(void)
+{
+	int err;
+
+	err = register_die_notifier(&nmi_nb);
+	BUG_ON(err);
+}
+
+void kmemcheck_pause_allbutself(void)
+{
+	int cpus;
+	cpumask_t mask = cpu_online_map;
+
+	spin_lock(&nmi_spinlock);
+
+	cpus = num_online_cpus() - 1;
+
+	atomic_set(&paused, 0);
+	atomic_set(&nmi_wait, 1);
+	atomic_set(&nmi_resume, 0);
+
+	cpu_clear(safe_smp_processor_id(), mask);
+	if (!cpus_empty(mask))
+		send_IPI_mask(mask, NMI_VECTOR);
+
+	while (atomic_read(&paused) != cpus)
+		cpu_relax();
+
+	atomic_set(&nmi_wait, 0);
+}
+
+void kmemcheck_resume(void)
+{
+	int cpus;
+
+	cpus = num_online_cpus() - 1;
+
+	atomic_set(&nmi_resume, 1);
+
+	while (atomic_read(&paused) != 0)
+		cpu_relax();
+
+	spin_unlock(&nmi_spinlock);
+}